Did my accumulator ball just die?

[aminga]

Following up on this: I bought a used power master from a board member. I changed out the pump today and now I can stop! Thanks YI Work for selling me a working power master system. Also thanks Aminga for answering all my questions and talking me out of buying that accumulator ball. I would probably still be on the waiting list. Now I have a extra and a sensor!

Skillet, let me jack this thread for a little idea I have.

Do you still have the old one. Up for an experiment with an automotive electric motor rebuilder I know?

If anyone's tried this chime in. When you look at the powermaster it's a pretty straightforward piece. It's for the most part a regular brake master cylinder with a hydraulic booster rather than a vacum booster. If you look at the body from the narrow part forward it's a plain old hydraulic brake master cylinder and it's rebuildable just like one. From that bulge back toward the firewall it's a hydraulic brake booster but even that's not that complicated. And that's rebuildable too just like a master cylinder.

The trouble spots are the accumulator ball, It uses nitrogen behind a diaphrma to keep the brake fluid under pressure. You see the brake fluid isn't compressible and the motor can't pump fast enough to keep the hydraulic booster under pressure as you step on the brakes and the piston in the booster moves forward. That's what the accumulator is for. Unfortunatly it's the diaphram ithat starts leaking allowing the ball to fill up with fluid so it can't keep up as you step on the brake. Unfortunatly you can't rebuild those but Cardone is apparently doing it for Kirbans.

That leaves the pressure switch. Don't know about those but it's just a pressure switch (that can withstand brake fluid)

The motor doesn't appear to be too much more than a 12 VDC electric motor much like a starter and those can be rebuilt.

 

[ahaer]

That leaves the pressure switch. Don't know about those but it's just a pressure switch (that can withstand brake fluid)

That switch costs as much as the accumulator now... $175 at poston's

When my powermaster failed for a 2nd time I went with a used vacuum conversion from gbodyparts.com $175 complete. It was a pain bending under the dash but at least I know I can get parts...

 

[Skillet]

Yes I still have the dead pump. I'd be willing to let somebody play with it as logn as they shared their results.

 

[zeus87gn]

...When you look at the powermaster it's a pretty straightforward piece. It's for the most part a regular brake master cylinder with a hydraulic booster rather than a vacum booster. If you look at the body from the narrow part forward it's a plain old hydraulic brake master cylinder and it's rebuildable just like one. From that bulge back toward the firewall it's a hydraulic brake booster but even that's not that complicated. And that's rebuildable too just like a master cylinder.

Yes, that's true. I rebuilt mine myself. Actually quite simple to do.

The trouble spots are the accumulator ball...Unfortunatly you can't rebuild those but Cardone is apparently doing it for Kirbans.

Correct and incorrect. No they can't be rebuilt; Cardone is building NEW ones for Kirbans.

That leaves the pressure switch. Don't know about those but it's just a pressure switch (that can withstand brake fluid).

Yes, it tells the motor when to trun on and off based on the pressure within booster side of the PM. Real simple...just getting expensive because it is rare.

The motor doesn't appear to be too much more than a 12 VDC electric motor much like a starter and those can be rebuilt.

Correct, but it has it's limitations. It doesn't have any cooling ability, so it can't run for long as it build up heat quickly. The drive motor probably can be rebuilt as long as the windings aren't melted, but to my knowledge the pump cannot be rebuilt. Hank Terry sells brand new ones that he manufactures with GM's original tooling. With brakes, it's no place to skimp. Don't waste your time messing with it unless you are really bored. Then you will give up...just like I did trying to get my old one apart. Been there, done that. No T-shirt available.

 

[ulose2av6]

hank terry?

he have a website? i hear alot about him but no # or anything

 

[zeus87gn]

http://www.members.tripod.com/Turbocars/pm.html